When stains occur on plastic in the course of machine dishwashing, this is usually caused by very intensely colored foods such as curry, paprika, tomatoes, red cabbage, ketchup, carrots, etc., which in the form of food residues are introduced into the dishwasher. Stains on plastic, such as plastic dishware, result in consumer dissatisfaction, since, although the affected plastic dishware remains undamaged on a purely functional level, this is perceived by many consumers as detrimental to the appearance, insufficiently cleaned, or at least esthetically displeasing.
Compounds for reducing the staining of plastics are described in patent application WO 02/064720, for example. The cited publication discloses that copolymers based on hydrophobically modified polycarboxylates suppress the staining of plastics.
International Patent Application WO 03/095602 discloses a method for removing colored soils on plastic, using a component having a density of 0.6 to 1 g/L, in particular paraffin oil and similar hydrocarbons, olive oil, and soybean oil.
WO 2010/078979 discloses the use of porous polyamide particles and synthetic layered silicates for reducing the staining of plastic dishware.
Detergents or cleaning agents containing hydrophobically modified polysaccharides such as hydroxypropyl celluloses are known from International Patent Applications WO 99/31211 and WO 2006/065848. These cellulose ethers have the advantages that they are compatible with salts, have inherently good solubility in various solvents, and are stable under acidic as well as alkaline conditions. The hydrophobically modified polysaccharides are suitable for numerous applications. As disclosed in WO 99/31211, they may also be used in machine dishwasher detergents, in particular solid machine dishwasher detergents. According to one example, dry powders containing hydrophobically modified polysaccharides may be easily manufactured. However, the cited publications do not mention the property of reducing stains on plastic dishware in machine dishwashing.
The object of the present invention is to provide further compounds for use in machine dishwasher detergents which at least reduce the occurrence of stains on plastics, due to colored food residues, in the course of machine dishwashing.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.